Simulation of CO2 injection and sensitivity analysis in a tight oil reservoir

Tight reservoirs, which are categorized as unconventional reservoirs, introduced significant challenges in oil extraction when compared to conventional reservoirs. In this simulation study, CMG-STARS simulator was employed to conduct six single-factor sensitivity studies (S-FSA) including porosity, pay thickness, permeability, injection rate, bottom-hole pressure (BHP), and temperature. The results indicated that porosity had the most pronounced impact on the change of cumulative production, accounting for 42.2%, followed by pay thickness, BHP, injection rate, and permeability, as reported in a prior study. Additionally, it was observed that carbon dioxide (CO2) exhibited a lower minimum miscibility pressure (MMP) of 2,014 psi when compared to the solution gas with 3,608 psi.